Edited Issue: image.Thumbnail not taking color adjustments properly [1385]

I have this code:

```
public MagickImage NewThumbImageTCBordered()
{
var image = ImageTC.Clone();
image.Resize(ThumbSize);
//image.Thumbnail(ThumbSize);
AdjustColor(image);
image.Write(ThumbFile().FullName);
return image;
}

public void AdjustColor(MagickImage image)
{
var color = View.Color;
if (color.Brightness != ColorAdjustments.BrightnessDefault
|| color.Contrast != ColorAdjustments.ContrastDefault)
image.BrightnessContrast(new Percentage(color.Brightness), new Percentage(color.Contrast));

if (color.Gamma != ColorAdjustments.GammaDefault)
image.GammaCorrect(color.Gamma);

if (color.Red != ColorAdjustments.RedDefault)
image.Evaluate(Channels.Red, EvaluateOperator.Add, color.Red);

if (color.Green != ColorAdjustments.GreenDefault)
image.Evaluate(Channels.Green, EvaluateOperator.Add, color.Green);

if (color.Blue != ColorAdjustments.BlueDefault)
image.Evaluate(Channels.Blue, EvaluateOperator.Add, color.Blue);
}

public static MagickGeometry ThumbSize
{
get
{
return _ThumbSize ?? (_ThumbSize = new MagickGeometry(ThumbSizeDTO.Size.Height));
}
}
static MagickGeometry _ThumbSize;

```

I've had to exchange image.Thumbnail(...) for image.Resize(...) because image.Thumbnail now makes negative (or blank) images based on the color modifiers .

Example:

Original Image

Adjust the image by adding 5 contrast. Image has also been flipped horizontally.

Thumbnail created with Resize

Thumbnail created with Thumbnail

I have this same problem appearing in multiple images, but not all images by adjusting any one or more of the colors or contrast. Haven't tested gamma, but it may also be affected. Contrast changes seems to break the thumbnail image sooner than color changes.

I have the most recent ImageMagick NuGet package as of today.